Why is the bumper made of plastic instead of steel?

First of all, I'd like to explain clearly here that bumper and anti-collision steel beam are completely different! Chinese people are very interested in the configuration of anti-collision beams. For example, some cars are not equipped with anti-collision steel beams, which are vomited by the majority of riders, but bumper users also know that bumper materials are plastic, whether Mercedes-Benz, BMW or domestic cars. It's all made of plastic! Why not use steel? Isn't the safety factor better? Let's take a look at the doorway here:

You know, in fact, the bumper used in the earliest car was indeed metal, but there was always the first car company that ate crabs, and that was Fiat! Fiat Auto Company used plastic bumper for the first time. Due to various factors, major car companies quickly followed suit, so that today's overwhelming car companies use plastic front and rear bumpers. What are their intentions?

First: the cost of plastic is low!

Bumper plasticization will undoubtedly reduce the cost of building a car, which is also one of the most important factors for car companies to consider. Nowadays, the automobile competition is very fierce, and cars want to occupy market share, so the price positioning of automobiles is extremely important. If you want to control the cost of cars, the most important thing is the price of plastics and metals. This needs no explanation. Plastic itself is relatively low in cost and easy to form, which is one of the reasons!

Second: lightweight design of automobiles!

With the increasingly stringent global emission standards, how to reduce emission pollution is also the top priority of car companies. If you want to reduce pollution and keep the power unchanged, you must design on lightweight. With the current automobile assembly line and molding, except that the body frame is made of high-strength rigid materials, other places that can be used are basically lightweight. In fact, the use of plastic materials has no advantages, such as corrosion resistance, easy molding, low maintenance and replacement costs. Finally, the price of cars to consumers is more reasonable.

Third: the safety performance is not low!

Some riders think that the safety factor of using steel plate bumper will be higher. In fact, the safety of a car is not determined by the bumper. Safety mainly depends on the design of the vehicle body frame, that is to say, the protection and material of the bumper can not determine the safety of the vehicle. Bumpers made of different materials may have small bumps and bumps, but they are vulnerable to relatively large collisions. Due to the material reasons, plastic is more elastic than metal and has better impact absorption capacity. Plastic bumpers can also play a certain buffering role in the event of collision, and have a certain protective effect on other vehicles, objects or pedestrians.

Summary: The function of bumper is actually different from that of anti-collision steel beam of automobile. The overall safety of a car cannot be determined by the bumper alone. Safety still depends on the overall coordination of the car. Since plastic bumpers can not only protect pedestrians, but also save energy and reduce emissions, why not? In fact, the owner may wish to use it as the coat of the car. Everyone must understand!

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Car bumper is made of plastic, which is mainly a safety device to absorb and buffer external impact and protect the safety of car body, pedestrians and passengers. When the car has a low-speed collision accident, it can play a buffering role and protect the front and rear car bodies; At the same time, it can protect pedestrians when they collide with them, because plastic has good collapsibility compared with other metal materials.

In fact, the early car bumpers were all made of metal, but with the significant improvement of safety awareness and continuous progress of technology, car companies gradually eliminated hard metal materials and turned to plastic to build bumpers. Except for the bumper, the car body is made of metal. When the vehicle collides at low speed, the bumper will limit its collapse and damage to the maximum extent because of its own characteristics, thus protecting other metal parts of the car body from external forces. This situation is easy to understand. The plastic material will break at most, but it will not transmit more impact force in other directions, and the metal panels in fender and other parts will not be deformed by external force.

In addition, in the case of frontal collision with pedestrians, the characteristics of plastic materials will also minimize the impact on pedestrians. In addition, there is still a distance between the bumper and the internal anti-collision steel beam, which can effectively protect pedestrians, especially the legs, at low speed. Another point is that the bumper made of plastic has the advantage of lower cost than that made of metal. For car owners, the cost of replacing such a huge part is very high, and the loss caused by plastic in the event of an accident is more economical than that caused by metal.

Many years ago, the front and rear bumpers of cars were mainly made of metal, and later they were replaced by plastic bumpers. Why is the bumper made of plastic? Mainly based on practical use and pedestrian safety considerations.

The front and rear bumpers of automobiles are mainly made of metal materials, which are generally stamped with steel plates and riveted or welded with the longitudinal beam of the frame. But then there was a better choice-plastic bumper.

Why on earth should the bumper be made of plastic? There are actually many reasons.

1. Considering pedestrian safety.

There is a simple reason. If the same car is driving at the same low speed (note that it is low speed, not high speed), it will hit a pedestrian in front. Imagine, if you were hit, would you like that bumper to be metal or plastic? If you don't understand, please try to find the relevant metal and soft plastic blunt objects to beat your head.

2. Based on practical considerations

Because bumpers are mostly made of elastic materials, they have good impact resistance. This means that small bumps can be easily solved, and it is not difficult to paint even if the paint falls off. This is a coup of "one is cheap and two are profitable"-car companies, car dealers and car owners can save time and money.

3. Principle of automobile bumper assembly

Moreover, it should be noted that if the bumper is made of plastic, the corrosion resistance will be better, otherwise, if the bumper often rusts, the owner is likely to get bored.

4. It is convenient for automobile design and production.

Automobile production has taken shape. In addition to the use of high-strength materials for the car body, many parts will be made of materials that are light, corrosion-resistant, easy to process, easy to shape and easy to maintain and replace.

Lightweight plastic bumper

The front and rear bumpers of the car are the same. Some external parts of automobile body, such as fender, can also be made of light materials, such as plastic. Of course, some sports cars will use a lot of carbon fiber materials instead of metal materials on the outer body. The purpose is simple: lighter body, faster and safer braking and more fuel-efficient.

If all the parts of a car are metal, how much should the car weigh? It is not so easy to slow down and brake instantly when an unexpected situation is found on the high speed.

But don't think it will make the car unsafe. The overall safety of the car, pay attention to the overall coordination, not the harder the parts, the safer the car.

Automobile body shell is mostly made of metal materials, such as steel plate, carbon fiber, aluminum, reinforced plastic and so on. The materials of automobile body shell and different parts are different for different purposes. Generally, it is steel plate, Audi luxury car is aluminum, racing car is carbon fiber, and the hood of Hummer H2 is FRP. The early body used the carriage body structure, and the whole body was mainly made of wood. 19 12, Edward Bart made the all-metal car body for the first time. 1925, Vincenzo Lancia invented the load-bearing car body, which consists of metal structural parts and large-scale panels formed by stamping steel plates. This kind of metal body has been used up to now, and it has been continuously improved and developed.

tin plate

Since 1970s, galvanized steel plates have been used for automobile body steel plates. Galvanized steel sheet is widely used in automobiles because of its good corrosion resistance. In the early years, it was found that when iron and zinc were put into salt water without any wire connection, both iron and zinc would rust, iron would produce red rust and zinc would produce "white rust"; If the two are connected by wires, iron will not rust, and zinc will produce "white rust", so zinc will protect iron. This phenomenon is called sacrificial anode protection. Engineers applied this phenomenon to actual production and produced galvanized steel plates. According to the research, when the galvanized amount is 350g/m2 (single side), the service life (red rust) of galvanized steel plate outside the house is about 15- 18 years in rural areas and about 3 15 years in industrial areas, which is several times or even more than that of ordinary steel plates.

Ordinary low carbon steel plate

In modern automobile production, the most commonly used is ordinary low-carbon steel plate. Low-carbon steel plate has good plastic processability, and its strength and stiffness can meet the requirements of automobile body and tailor-welded automobile body, so it is widely used in automobile body. In order to meet the lightweight requirements of automobile manufacturing industry, steel enterprises have introduced high-strength steel series plates for automobiles. This kind of high-strength steel plate is obtained by strengthening method on the basis of low-carbon steel plate, and its tensile strength is greatly enhanced. Using the high strength characteristics, the mechanical performance requirements of the automobile body can still be maintained under the condition of thinning, thus reducing the weight of the automobile. For example, BH steel plate is baked and heat-treated after stamping under low strength conditions to improve its tensile strength. In contrast, the steel plate with the strength of 440MPa produced in the past can be improved to 500MPa after this processing technology is adopted. The original side plate is a steel plate with a thickness of 1 mm, while the high-strength steel plate only needs to be 0.8 mm thick ... The use of high-strength steel plate can also effectively improve the impact resistance of the automobile body, prevent dents caused by sand splashing and collision on the road surface during driving, and prolong the service life of the automobile.

High strength steel plates for vehicles should have the characteristics of high strength and good ductility. At present, high-strength steels include BH steel (paint hardened steel plate), dual-phase DP steel, phase transformation induced plasticity steel (TRIP), microalloyed M steel and high-strength seamless solid solution IF steel. It is generally used for parts that require high strength, high anti-collision energy absorption and strict molding requirements, such as rims, reinforcements, bumpers and bumpers. With the development of performance and forming technology, high-strength steel plates are used in automobile inner and outer panels, such as roof, door inner and outer panels, engine compartment cover, luggage compartment cover and so on. Nowadays, many middle and high-grade cars use high-strength steel plates.

In recent years, more and more non-steel materials, such as aluminum or plastic, have been used as body parts of mid-to-high-end cars, such as Audi A2 all-aluminum body, the front fender of Nissan SUV Qi Jun is made of plastic, and more passenger car bumpers are made of plastic.

Many people think that the car body is safe and unsafe. What is important is that the car body is firm and not firm. The thicker the steel plate, the safer it is. However, modern automobile design does not consider this. From the perspective of mechanical research, designers think that the soft place is soft and the hard place is hard. According to different stress conditions, some car bodies can absorb energy and disperse it during collision, so as to minimize the impact force. The purpose of protecting drivers and members to the maximum extent has been achieved.

1 The appearance looks beautiful, and it is convenient to make any shape you want. Two tanks collided and absorbed energy relatively. For example, the external parts are not damaged much, but the internal components can't stand it, which may be fatal.